This problem began occurring within the past couple of days, and to my knowledge I made no changes to any hardware or to my network layout.

I have a Windows 8 PC connected to a gigabit switch (D-Link DGS-2205) on the LAN side of a WRT54G router running Tomato Firmware v1.25.1720, and two laptops connected to the router by wifi, one Windows 8, and one XP. The router's WAN port is connected to a switch (SMCFS8) which is in turn connected to my ADSL modem. My TV is ADSL and is also connected to the modem via the switch.

The problem is: After suspending my Windows 8 PC at night, in the morning the WRT54G has lost internet connectivity (LAN still works).

Power cycling the router doesn't help

Power cycling the modem doesn't help

Waking or rebooting either of the laptops connected to wifi doesn't help (they can connect to the router via wifi, but the router has no internet connectivity)

The TV works during this time

What does work: is waking the Windows 8 PC from sleep, which immediately resolves whatever issue the router was having, allowing it to obtain a DHCP lease, and internet connectivity is restored for all of the computers. Update: Unplugging the sleeping windows 8 machine's LAN cable also restores connectivity. This makes me think there is possibly something electrical going on? Or WOL related?

If I just suspend my PC at a random time while I'm at home, internet connectivity may be lost almost immediately or much later.

What is going on?

I will continue looking into the issue and post a resolution if I find one.

Is UPnP somehow messing with the router's ability to connect, and the Windows 8 PC is either notifying or resetting the router in some way that allows it to re-connect.

Update: UPnP is now disabled under the Port Forwarding area of Tomato's interface, this doesn't appear to have made a difference.

The only hardware related change I made recently was plugging my printer into my Windows 8 PC through USB for the first time since I upgraded to Win8

The only software change I made was installing a game on the Windows 8 PC that I uninstalled the next day

No network topology changes had happened for a week or two prior to the issue beginning

At this point I'm more interested in knowing the root cause out of curiosity than actually resolving the issue, although that would be a nice benefit.

Is there a reason why you're running 1.25 and not the latest version, 1.28? Is this a mod of Tomato or the stock release? Why the switch in front of the router and is the WAN port set to be part of the LAN bridge?
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philamonsterJan 12 '13 at 19:10

I haven't upgraded the tomato firmware because I've never had reason to, it has worked fine for years. The switch is in front of the router as both my router and tv-box box need to be connected to the adsl modem.
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Brook MilesJan 12 '13 at 19:34

almost sounds like an ip or mac address conflict. maybe a rogue device is duplicating one or the other. might also try disabling ipv6 in the win8 box and see if that provides a clue.
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user168261Mar 9 '13 at 21:54